It is often necessary to isolate a precision transducer from external stress. Such stress may be caused by mechanical distortion of the case or other structure to which the transducer is mounted, or by differential thermal expansion or contraction between the transducer and the case. Isolation from external stress can in principle be achieved by using a compliant mounting system. However, a compliant mounting system will not in general provide precise and stable alignment of the transducer with respect to its case. For many transducers, such alignment is critical for achieving proper operation. A compliant mounting system may also result in unwanted mechanical oscillation of the transducer when the case is exposed to vibration.
One type of precision transducer that is especially susceptible to external stress is an accelerometer. This is due, in part, to the extreme level of accuracy being sought. An accelerometer is an example of an instrument that must not be allowed to change position or vibrate with respect to its case. One prior accelerometer mounting technique has been to connect the accelerometer to the case by means of a metal ring or by means of a structural adhesive such as an epoxy resin. These prior non-compliant mounting techniques result in stress being transmitted to the accelerometer due to differential thermal expansion between the accelerometer and the mounting ring and case. These prior techniques also transmit stress to the accelerometer when the case is subjected to mechanical distortion. Distortion can be induced by mounting the case to a surrounding support, or by differential thermal expansion between the case and the support. Dimensional instabilities in epoxy joining materials can occur, especially at elevated temperatures. All such stresses may affect the output of a precision accelerometer, and may result in reduced stability. The temperature induced stresses also may lead to increased variation of accelerometer output with temperature, and may create thermally induced errors in the accelerometer output. Thus, an improved mounting system for a precision transducer would be an advance in the art that would be greatly welcomed.